Spincasting (AKA centrifugal rubber mold casting) is a process starting with a master pattern used to make a rubber mold which is used to cast production patterns or parts. Materials commonly cast using the spincasting technique are plastic resins, wax(for investment casting), tin or lead alloys, and zinc-aluminum. Tooling (rubber molds) are relatively low cost compared to hard tooling. Parts can be made with excellent surface finish and fair to good dimensional tollerances. Many if not most complex shapes (often done as investment castings) can be spincast. Spincast resin can have surface finishes nearly as nice as injection molded parts.

I have been spincasting for about 5 years with spincast parts being used in my model products as well as spincasting for other model makers. I have spincast parts in polyurethane resin, Britannia metal, and zinc-aluminum.

My casting equipment consists of 9"-12" analog and 9"-18" digital spincasting machines, 12" analog vulcanizer, 18" digital vulcanizer, electric melt pot, gas melt pot, vaccuum bell jar and an assortment of lesser tools.

Patterns can be of a variety of materials but metal patterns are preffered since they can be used directly to make a vulcanized mold. I usually make my patterns from plastic or brass using manual machining and fabrication methods. I am just starting to use a small cnc mill on patterns and plan to start using 3D printing for some patterns. Plastic patterns require that RTV rubber is used for a mold to cast metal production patterns to make vulcanized molds.

As a scale model maker I find that spincasting offers an economical method to produce short runs of parts. I offer spincasting, limited to scale model parts, as a service. In addition to spincasting I offer resin casting in RTV molds.


Jack Mc Kie
www.freshwatermodels.net